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Prior Performance and Risk-Taking of Mutual Fund Managers:
A Dynamic Bayesian Network Approach
Manuel Ammann and Michael Verhofen∗
October 2006
forthcoming in the Journal of Behavioral Finance, 8(1), 2007
Abstract
We analyze the behavior of mutual fund managers with a special focus on the impact of
prior performance. In contrast to previous studies, we do not solely focus on the volatility
as a measure of risk, but also consider alternative definitions of risk and style. Using a
Dynamic Bayesian Network, we are able to capture non-linear effects and to assign exact
probabilities to the mutual fund managers' adjustment of behavior. In contrast to theoretical
predictions and some existing studies, we find that prior performance has a positive impact
on the choice of the risk level, i.e., successful fund managers take more risk in the
following calendar year. In particular, they increase the volatility, the beta and the tracking
error and assign a higher proportion of their portfolio to value stocks, small firms and
momentum stocks. Overall, poor performing fund managers switch to passive strategies.
Keywords: Mutual Funds, Risk Taking, Dynamic Bayesian Network JEL classification: G21
∗ Manuel Ammann ([email protected]) is professor of finance at the Swiss Institute of Banking and Finance, University of St. Gallen, Switzerland, and Michael Verhofen ([email protected]) is visiting scholar at the Haas School of Business, University of California at Berkeley. We thank the editor, Bernd Brommundt, Alexander Ising, Stephan Kessler, Axel Kind, Jennifer Noll, Angelika Noll, Ralf Seiz, Stephan Süss, Rico von Wyss, and Andreas Zingg for valuable comments. We acknowledge helpful comments of the participants from the Joint Research Workshop of the University of St. Gallen and the University of Ulm in 2005. We acknowledge financial support from the Swiss National Science Foundation (SNF).
1 Introduction
The behavior of mutual fund managers has been subject to considerable academic research.
As rational agents, they are supposed to adjust their behavior in consideration of the
incentives they are facing. Basically, these incentives can be divided into two different
aspects, the structure of compensation schemes and the behavior of investors. On the one
hand, most compensation schemes are constructed like a call option, i.e., fund managers
have a higher upside than downside potential. This provides a temptation for fund
managers to increase the riskiness in a suboptimal way for the investor. On the other hand,
in a multi-period context, a positive relation between past performance and new fund flows
has been observed. A fund manager who has shown a high performance is rewarded with
new capital. In contrast, a manager with a poor performance does not suffer from the same
amount of cash outflows. If compensation is linked to fund size, this provides an incentive
for increasing the riskiness of a portfolio to a suboptimal point from an investor’s
perspective. In short, in so called mutual fund tournaments portfolio managers compete for
better performance, greater fund inflows, and higher compensation.
From a theoretical point of view, a number of authors focus on agency conflicts in the
mutual fund industry, i.e., on asymmetric information and hidden action between mutual
fund managers and their investors, and on the call option-like function of compensation
schemes. Fund managers might unnecessarily shift the fund’s risk in response to the fund’s
relative performance. This behavior is linked to compensation and investor’s reaction.
Carpenter (2000) solves the dynamic investment problem of a risk averse manager
compensated using a call option on the assets he controls, i.e., a convex compensation
scheme. She shows that under the manager’s optimal policy, the option is likely to end up
deep in or deep out of the money because managers take, in general, more risk than the
2
investor would choose. Berk & Green (2004) propose a model that incorporates two
important features: First, performance is not persistent and, second, fund flows rationally
respond to past performance. In particular, they assume that investors behave as Bayesians,
i.e., they update their beliefs about a fund manager’s skill based on observed returns and
prior beliefs. They show that a rational model for active portfolio management when talent
is a scarce resource disappearing as a fund grows can explain many empirical observations
without relying on investors irrationality and asymmetric information. Similar models also
relying on Bayesian updating have been proposed by Schmidt (2003) and Dangl, Wu &
Zechner (2004). Lynch & Musto (2003) address the question how fund managers change
their strategy over time. In their model, they show that strategy changes only occur after
periods of poor performance.
From an empirical point of view, different authors have analyzed the actual behavior of
mutual fund managers. Deli (2002) investigates marginal compensation rates in mutual
fund advisory contracts. He finds that marginal compensation depends positively on
turnover and the fund type (e.g. equity, closed-end), and is negatively related to fund size
and size of the fund family. Therefore, incentives to take risk might differ across fund
managers.
Chevalier & Ellison (1997) estimate the shape of the relationship between performance and
new fund flows because the shape of this relation creates incentives for fund managers to
increase or decrease the riskiness of the fund. They find that funds tend to change their
volatility depending on the relative performance by the end of September. Similarly,
Brown, Harlow & Starks (1996) focus on mid-year effects. In particular, they test the
hypothesis that mutual managers showing an underperformance by mid year change the
fund’s risk differently than those mutual fund managers showing an outperformance at the
3
same point in time. Their empirical analysis shows that mid-year losers tend to increase the
fund’s volatility to a greater extent than their successful counterparts. Busse (2001)
suggests that some prior findings might be spurious. Using daily data and the methodology
by Brown et al. (1996) he finds no mid-year effect. In sum, existing empirical analyses
have failed to deliver clear evidence on the behavior of mutual fund managers and there
are doubts about the robustness of the findings.
In this paper, we contribute to the existing empirical literature in a number of ways. In
contrast to existing studies, we do not solely focus on volatility as a measure of risk. We
take into account also other measures such as the beta and the tracking error, and style
measures such as the high-minus-low (HML) factor, the small-minus-big (SMB) factor,
and the momentum (UMD) factor. Furthermore, in contrast to previous studies, we use a
robust, non-parametric approach. As we do not impose any distributional assumptions, we
are able to capture a wide range of non-linear and asymmetric patterns. Moreover, instead
of using a particular theoretical model describing the behavior of fund managers as a
starting point, our study is designed in an explorative way. Concerning the data, we do not
use only a sub-group of mutual funds, but a complete set of all US equity funds for a long
time period of data.
In this paper, we compute conditional transition matrices and compare whether the
conditional transition matrices are different for successful and unsuccessful mutual funds.
For the empirical analysis, we use a Bayesian Network. A Bayesian Network is a model
for representing conditional dependencies between a set of random variables. Up to now,
research on Bayesian Networks (BN) is mainly concentrated in statistics and computer
science, particularly, in artificial intelligence (Korb & Nicholson (2004), Neapolitan
(2004)), in pattern recognition (Duda, Hart & Stork (2001)) and expert systems (Jensen
4
(2001), Cowell, Dawid, Lauritzen & Spiegelhalter (2003)). However, although the term
“Bayesian Network” has not yet widely spread, special cases of Bayesian Networks are
widely used in economics and finance. In particular, many state space models such as the
Kalman filter and Hidden Markov models are Bayesian Networks with a simple
dependency structure. Moreover, many classical econometric approaches such as discrete
choice models and regressions are so-called Naive Bayesian Networks because of their
mono-causal dependency structure (Jordan, Ghahramani & Saul (1997)).
Bayesian Networks work as follows. Suppose there are three variables such as the tracking
error in period T, the return in period T, and the tracking error in period T + 1. Suppose
next that all variables are conditionally dependent, i.e., the tracking error in period T
affects the return in period T and the tracking error in period T + 1. Moreover, also the
return in period T affects the tracking error in T + 1. In classical econometrics, this
problem is determined as multicollinearity and might lead to identification problems.
Bayesian networks can deal with such complex settings and can help to overcome the
identification problem. For a discussion of a wide range of different settings of Bayesian
Networks, we refer to Pearl (2000).
Besides being a modern tool for identifying the impact of and magnitude of different
causal sources, using Bayesian Networks has a number of advantages over standard
econometric methods. For example, they allow the computation of exact conditional
probabilities to assess the magnitude of a factor. For example, we can analyze whether the
probabilities change from 50:50 to 60:40 or to 90:10 for a given evidence. Moreover,
Bayesian Networks are able to capture non-linear and asymmetric patterns.
Using Bayesian Networks on a set of US equity funds over about 20 years of data, we find
that prior performance has a positive impact on the choice of the risk level, i.e., successful
5
fund managers take more risk in the following time period. In particular, they increase the
volatility, the beta, and the tracking error and assign a higher proportional of their portfolio
to value stocks, small firms and momentum stocks.
The article is structured as follows. In Section 2, we outline the econometric approach. In
Section 3, we present our empirical results. Section 4 concludes.
2 Model
2.1 Introduction to Bayesian Networks
We start with a description of Bayesian Networks. For short, a Bayesian Network is a
graphical model for representing conditional dependencies between a set of random
variables. This includes, in particular, learning about conditional distributions and updating
beliefs about probability distributions for a target node given some observation for at least
one variable.
Figure 1 shows a Dynamic Bayesian Network. The structure is similar to the Bayesian
Networks which have been proposed by Pearl (2000) for causal discovery. The circles
denote the nodes, i.e., the variables in the Bayesian Network, and the arcs the conditional
dependency between two nodes. The conditional dependency between two nodes can be
basically of any type. The most frequently conditional probability distributions (CPD) used
are Gaussian distributions and multinomial (or tabular) distributions. In the example in
Figure 1 a binomial distribution is used.
We are using a Dynamic Bayesian Network to analyze the revision of behavior in the
mutual fund industry. In particular, we analyze how past performance affects a set of
6
variables which describe the risk taking behavior of mutual fund managers. Suppose a fund
manager can, at least to some degree, choose the tracking error of his portfolio, i.e., how
close he mimics the relevant index or whether he chooses a more active investing style. By
assumption, there is a fifty-fifty chance that the portfolio manager chooses a high or low
tracking error. Suppose next that the choice of the magnitude of the tracking error affects
the subsequent return. In particular, a low tracking error leads to a chance of 50% of a high
return and to 50% of a low return. In contrast, it is assumed, that a high tracking error leads
to a chance of 90% of a low return and 10% of a high return.
The tracking error in period T + 1 is an effect of two variables, the tracking error in period
T and the return in period T. These conditional dependencies have a straightforward
interpretation. On the one hand, it might be that there is some degree of persistency in the
behavior, i.e., a fund manager who has had a high tracking error in period T tends to
maintain a high tracking error. On the other hand, there might be some degree of learning
or revision of behavior.
Figure 1 shows how the Dynamic Bayesian Network can be used to update beliefs about
probability distributions. Suppose the investor knows that a fund had a superior
performance in period T. The question of inference is how this knowledge affects the belief
about the distribution of the tracking error in period T + 1. As shown in Figure 1, the
straightforward application of Bayes theorem leads to a probability of 91.50% for a high
tracking error and of 8.5% for a low tracking error.
Bayesian Networks are frequently also denoted as probabilistic networks (Cowell et al.
(2003)), Bayesian Artificial Intelligence (Korb & Nicholson (2004)) and Bayesian Belief
Networks (Duda et al. (2001)). As noted by Borgelt & Kruse (2002), Bayesian Networks
7
rely on the achievements of a number of other concepts and in particular on classification
and regression trees, naive Bayes classifiers, artificial neural networks and graph theory. A
number of other econometric approaches such as the Kalman Filter, Hidden Markov
Models and state space models in general can be regarded as special cases of Bayesian
Networks and, in particular, of Dynamic Bayesian Networks (DBN), as shown by Jordan et
al. (1997). Even regressions and discrete choice models can be incorporated in a Bayesian
Network structure such as in so-called Naive Bayes Nets. Bayesian Networks (BN) are a
very powerful tool to deal with uncertainty, incomplete information and complex
probabilistic structures. In particular, Bayesian Networks enable the extraction of
probabilistic structures from data and decision making in these structures. Therefore,
Bayesian Networks are well-suited for financial applications.
In this section, we address the three main issues associated with Bayesian Networks. First,
the question of representation, i.e., what is a Bayesian Network. Second, the question of
learning (estimation) of parameters of a Bayesian Network. Third, the question of
inference, i.e., how Bayesian Networks can be used to answer probabilistic questions. For
an extended coverage of the topic and for a coverage of decision making within Bayesian
Networks, we refer to Jensen (2001), Cowell et al. (2003), Korb & Nicholson (2004) and
Neapolitan (2004).
2.2 Representation
As defined by Jensen (2001), a Bayesian Network consists of a set of variables with
directed arcs between these variables. These variables form a directed acyclic graph
(DAG) and, for each arc that connects two variables, a potential table, i.e., a conditional
distribution, is defined.
8
Suppose there are four random variables, A, B, C, and D. Applying the chain rule, the joint
probability can be written as a product of conditional probabilities
=),,,( DCBAP ⋅),,|( CBADP ⋅),|( BACP ⋅)|( ABP )(AP . Suppose next, A and D are
conditionally independent, i.e., ⋅= ),|(),|,( CBAPCBDAP ),|( CBDP and B and C are
conditionally independent. Using Bayes theorem and the previous factorization, it can be
shown that
. ),|()|()()(
),|()|()()(),(
),,,(),|,(
dAdDCBDPACPBPAPCBDPACPBPAP
CBPDCBAPCBDAP
⋅⋅⋅∫∫
⋅⋅⋅=
=
Basically, three elementary theorems of probability, i.e., Bayes theorem, the chain rule,
and conditional dependency, are the building blocks for Bayesian Networks.
2.3. Learning
In the previous subsection, we assumed that the parameters, i.e., the conditional probability
distributions, are known. However, in most cases it is necessary to learn about the
parameters of a Bayesian Network based on a data set. For parameter learning, maximum
likelihood (ML) can be used. As noted by Ghahramani (2001), the likelihood decouples
into local terms involving each node and its parents. This simplifies the maximum
likelihood estimation because it reduces to number of local maximization problems.
Suppose a data set consists of M cases for each of the n nodes. Let
denote the vector of observations for a single case for all nodes in the network. Therefore,
the training data set d is given
( )′= )()(
1)( ,..., h
nhh ddd
{ })()2()1( ,...,, Mdddd = . Neapolitan (2004) shows that the
likelihood function is given by
9
),|()|( )()(
11i
hi
hi
M
h
n
i
padPdL θθ ∏∏==
=
where contains the values of the parents of the node X)(hipa i in the hth case and θ the
parameter set.
In this paper, we use a multinomial distribution. In this case, the maximization problem
simplifies to a closed-form solution if the data are complete. Then, the likelihood function
is given by
, )(111
⎟⎟⎠
⎞⎜⎜⎝
⎛= ∏∏∏
===
ijkiji
sijk
r
k
q
j
n
i
FEdL
where qi denotes the parents of node Xi and ri the number of different classes of the
multinomial distribution. Fijk denotes the distribution of node i conditional on the parent
node j where the value of node xi is equal to k. The exponent sijk denotes the number of
cases in which xi is equal to k. The proof of these results can be found in Neapolitan
(2004). Suppose next the conditional distributions Fijk have a Dirichlet distribution, i.e., a
generalized Beta distribution, with (prior) parameters and
Then, the likelihood is given by
,1ija ,...,2ija ,iijra ijkkij aN ∑=
.ijkkij sM ∑=
)()(
)()(
)(111 ijk
ijkijkr
kijij
ijq
j
n
i asa
MNN
dLii
Γ
+Γ
+Γ
Γ= ∏∏∏
===
where denotes the gamma function. The use of Dirichlet distributions as conditional
distribution has a couple of advantages and is not restrictive at all. The Dirichlet
distribution is the so called natural conjugate prior for the multinomial distribution, i.e., an
application of Bayes theorem with the Dirichlet distribution as prior distribution and the
multinomial distribution as likelihood leads to a closed form solution for the posterior
distribution which has the same functional form as the prior, i.e., a Dirichlet distribution.
(.)Γ
10
Therefore, the Dirichlet distribution is very helpful for Bayesian sequential analysis and
Bayesian updating. Moreover, the Dirichlet distribution has upper and lower bounds and is
therefore very helpful for modelling probabilities that cannot become greater than 1 or
lower than 0. Concerning prior information, we can incorporate prior information about
conditional dependencies or assign almost uninformative priors by setting all aijk to 1.
2.4. Inference
Suppose, the structure of a Bayesian Network and all conditional probability distributions
(CPD) are known and a researcher has evidence about at least one node for a new case.
The goal of probabilistic inference (also belief updating, belief propagation or
marginalization) is to update the marginal probabilities in the network to incorporate this
new evidence (Ghahramani (2001)). Formally, the task of inference is to find the posterior
distribution , where X denotes the query node and E the set of evidence
nodes.
)|( eExXP ==
By using the local structure of a Bayesian Network, it can be shown that belief updating
can be divided into the predictive support for X from evidence nodes connected to X
through its parents, U1,…,Um, and the diagnostic support for X from evidence nodes
connected to X through its children, Y1,…,Ym (Korb & Nicholson (2004)). Pearl’s message
passing algorithm (Pearl (1982)) shows how to update the posterior distribution Bel(X).
The derivation involves the repeated application of Bayes Theorem and the use of the
conditional independencies encoded in the network structure. The basic idea is that, at each
iteration of the algorithm, Bel(X) is updated locally using three parameters, λ(X), π(X) and
the conditional probability table (CPT), where λ(X) and π(X) are computed using the
messages received from the parents π and from the children λ of node X (Korb &
11
Nicholson (2004)). In Bayes Theorem, π plays the role of the prior and λ the role of the
likelihood.
The algorithm requires three types of parameters to be maintained. First, the current
strength of the predictive support π contributed by each incoming link , i.e., XU i →
),|()( \ XUiiX iEUPU =π where is all evidence connected to UXUi
E \ i except via X. Second,
the current strength of the diagnostic support λ contributed by each outgoing link
)|()(: \ XEPXYX XYYj jj=→ λ where is all evidence connected to YXY j
E \ j through its
parents except via X. Third, the fixed conditional probability distribution (CPD)
, i.e., the conditional distribution of node X is only dependent on its
parents.
),...,|( ni UUXP
Pearl’s message-passing algorithm consists of two steps. In the first step, i.e., belief
updating, messages arriving from the parents or the children of an activated node X and
lead to changes in belief parameters. In the second step, i.e., bottom-up and top-down
propagation, the activated node computes new messages for the parents λ and for the
children λ to send it into the appropriate direction.
In the first step, the posterior distribution of each activated node X proportional to the
messages from the parents )( iX Uπ and to the messages from its children )(XjYλ is
determined as follows
)()()( iii xxxBel παλ=
where )(),...,|()( 1,...,1
iXi
niuu
i uuuxPxn
ππ ∏∑= and
12
⎪⎩
⎪⎨
⎧
∏
==
otherwise )(another for is evidence if 0
is evidence if 1)(
iYj
j
i
i
xx
xXx
jλ
λ
and where α is a normalizing constant rendering .1)( ==∑ ix xXBeli
In the second step, the bottom-up and top-down propagation step, node X sends new λ
messages to its parents
)(),...,|()()(:
kXik
niiiku
ix
iX uuuxPxuki
πλλ ∏∑∑≠≠
=
and the new π messages to its children
⎪⎩
⎪⎨
⎧
=otherwise )(/)(
lueanother vafor is evidence if 0entered is valueevidence if 1
)(
iYi
j
i
iY
xxBelx
xx
j
j
λαπ
This procedure is repeated until a node has received all messages.
Inference methods can be distinguished into two main categories, exact inference and
approximate inference algorithms. The latter have been developed because probabilistic
inference can be a computationally hard problem for complex networks with a large
number of nodes because required computational power increases exponentially with the
number of parent nodes. Well-known algorithms for exact inference include variable
elimination, Pearl’s message-passing algorithm, the noisy-or-gate algorithm, and the
junction tree algorithm. For approximate inference, standard algorithms include likelihood
weighting, logic sampling and Markov Chain Monte Carlo (MCMC) (for an overview, see
Korb & Nicholson (2004) or Neapolitan (2004)).
2.5. Data
13
For the analysis, we use a complete sample about all US open-end equity funds containing
1923 funds. The data set has been provided by Reuters Lipper. For each single fund,
information about the fund’s launch date, the fund’s sector (Equity, International, Large
Cap, Mid Cap, and Small Cap), its style (Income, Core, Growth, Value), its annual fee and
its total assets per April, 30th, 2004, are available. Price information is available on a
monthly basis for 19 years, i.e., from December 1984 to December 2003. For the analysis,
we exclude international mutual funds and funds with less than two years of data. For
benchmarking purposes, we use the excess return on S&P 500 index as the market
portfolio and the 3-month Treasury bill rate as the risk-free rate. The data are from
Datastream. As a second benchmark, the Carhart (1997) four-factor model is used. The
data for the market risk premium, the size premium, the value premium and for the
momentum premium, are from the Fama and French data library.
Table 1 shows the descriptive statistics for the data used in this study. The number of funds
increased from 191 in year 1985 to 1478 in the year 2003. The average return across all
funds fluctuated substantially during that time with a minimum of -26.35% in 2002 and a
maximum of 28.26% in 2003. Similarly, the performance of single funds shows a high
degree of dispersion.
2.6. Performance Measurement
To measure a fund’s performance, a number of different approaches have been suggested
(e.g. Kothari & Warner (2001), Wermers (2000), Daniel, Grinblatt, Titman & Wermers
(1997)). To estimate the exposure towards the Fama & French (1993) risk factors and the
Carhart (1997) momentum factor, we run the following regression for each fund i and for
each calendar year t:
14
tiCarhartUMDtiSMBti
HMLtiCarharttiCarharttiCarharttfti
rUMDrSMB
rHMLrMRPrr
,,,,
,,,,,,,
ε
α
+⋅+⋅
+⋅+⋅+=−
where ri,t denotes the return of a fund i, rf,t the risk-free rate and εCarhart,i,t the regression
residual. The coefficients to be estimated are denoted by MRPCarhart,i,t, HMLi,t, SMBi,t and
UMDi,t, and risk premia by rCarhart, rHML, rSMB and rUMD. An analogous approach is used for
the risk exposure with respect to the S&P 500, i.e.,
. ,,500500,,500,,500,, tiSPSPtiSPtiSPtfti rMRPrr εα +⋅+=−
In the following analysis, we refer to titiRaw rR ,,, = as the unadjusted return of a fund, to
tiSPtiSPR ,,500,,500 α= as the risk-adjusted return using the S&P 500 as benchmark, and to
tiCarharttiCarhartR ,,,, α= as the risk-adjusted return using the Carhart four-factor model as
benchmark.
The tracking error measures a fund's deviation from a passive index. We define the
tracking error TE as the volatility σ of the residuals of the regressions on the index, i.e.,
. )( and )( ,,500,,500,,,, tiSPtiSPtiCarharttiCarhart TETE εσεσ ==
2.7. Implementation
Figure 2 shows the corresponding Dynamic Bayesian Network. For each fund, we estimate
for each year eight different factors describing the behavior of a mutual fund. In particular,
we use the standard deviation of returns, the beta against the S&P 500 and the Fama and
French market portfolio, the loading on the value vs. growth factor, the loading on the size
factor, the loading on the momentum factor, and the tracking error against the S&P 500
and the Fama and French market portfolio.
15
A likelihood ratio test was performed and showed that all arcs in the Bayesian Network are
highly significant.
To get robust results that are independent of restrictive distributional assumptions and to
incorporate non-linear behavior, we use a multinomial distribution with four classes where
variables are grouped into quartiles for each year.
The implementation of the Bayesian Network has been carried out using the “Bayes Net
Toolbox for MatLab”. For testing, we created a large number of different artificial data sets
and re-extracted the underlying probability distributions. In all instances, the underlying
probability distributions were recovered accurately.
The Bayesian Network has been initialized by setting all aijk to 1. Therefore, the analysis
incorporates no material prior information. The Bayesian Network is primarily used as an
econometric tool.
3. Empirical Results
The analysis is structured as follows. We first focus on the marginal distributions within a
time period that is the relation between risk and return. Then, we focus on intertemporal
relations of different measures of risk and style. Finally, we turn to the marginal
distributions of risk and style conditional on past performance.
Due to the large amount of empirical results, we focus in the empirical part on risk-
adjusted returns using the S&P 500 as benchmark in a one-factor model. If not stated
otherwise, results for unadjusted returns and returns adjusted with the Carhart four-factor
model are very similar.
3.1. Risk and Return
16
Table 2 shows the relation between the set of variables describing the risk exposure of
mutual funds and the following performance measured on a risk-adjusted basis.
Significance has been tested against a null hypotheses of no probabilistic relation, i.e., the
null hypothesis for a multinomial distribution with four classes is that the probability for
each class is 25%.
Table 2 is interpreted as follows. Suppose a fund has in one particular year a volatility in
the lowest quartile among all other funds. Then, the fund has a probability of 11.8% (first
row, first column) to achieve a risk-adjusted return in the lowest quartile among all other
funds. Analogously, the chance is 30.8% (first row, fourth column) to obtain a risk-
adjusted return in the highest quartile among all other funds.
We find that the higher the volatility, the more likely a fund has an extreme return in
quartile 1 (Q1) and quartile 4 (Q4). The transition probability of ending in the first quartile
of returns is only 11.8% for funds with a volatility in Q1 and 22.8% for funds with a
volatility in Q4. Similarly, funds with a low standard deviation in Q1 have a chance of
30.8% of reaching a high return in Q4 whereas funds with a high standard deviation in Q4
have a chance of 41.4%. Consequently, funds with a low risk level have a higher chance of
reaching a return centered around the mean. For example, a fund with a volatility in Q1 has
a chance for a return in Q2 of 28.9% whereas a fund with a high volatility fund has a
chance of 16.6%.
For the exposure to the market risk, i.e., the beta, the finding is reversed. Funds with a low
beta in Q1 have a chance of 42.6% of achieving a risk-adjusted return in Q4. High-beta
funds have only a transition probability to a return in Q4 of 33.0%. The data show that the
higher a fund’s beta is, the lower is its relative risk-adjusted return.
17
The style factors in the Carhart (1997) four-factor model, i.e., the value premium, the size
premium and the momentum premium (UMD), show the expected results. As documented
by Fama & French (1993), trading strategies based on size factors and valuation ratios
have historically earned superior returns. Value oriented funds, i.e., funds with a high
loading on the value premium (HMLT in Q4) had a chance for a return in Q4 of 44.2%. In
contrast, growth funds (HMLT in Q1) had a chance for a return in Q4 of 32.6%. Similarly,
small-caps funds, i.e., funds with SMBT in Q4, had a chance for a return in Q4 of 44.4%,
while for large cap stocks this value was only 24.2%. Even more evident is this findings
for momentum funds. Funds with a high exposure to momentum stocks (Q4) had a 49.4%
chance for a return in the highest quartile. Vice versa, for funds avoiding momentum
stocks (Q1), this chance is reduced to 17.0%.
The tracking error indicates the magnitude of active portfolio management of a fund
manager. The transition matrix shows that fund managers with a high tracking error (Q4)
are with 45.8% more likely of having a return in the highest quartile than fund managers
with a low tracking error (Q1) having a chance of 25.%. The data indicate that active
portfolio management has had some value.
3.2. Persistence in Risk Levels
In this section, we analyze the persistence in the choice of risk levels. Table 3 shows the
relation between a measure of risk, e.g., the standard deviation, in period T and the
successive period T + 1. Of special interest are the diagonal elements of the transition
matrix because they represent the degree of persistence in the choice of risk levels.
For the standard deviation the probabilities of staying in the same quartile, i.e., the
diagonal elements of the transition matrix, are 50.4%, 37.8%, 41.2%, 70.1%, respectively.
18
This means that a fund with a low return volatility has a chance of 50.4% of staying in the
lowest quartile, a fund with a volatility in the second quartile of 37.8% of staying in the
same quartile, and so on. In contrast, for the exposure towards market risk, the data show a
lower degree of persistence in behavior. For the beta against the S&P 500 only 46.0%,
31.0%, 36.4%, 54.1%, respectively, stay in the same class. Therefore, we conclude that the
fund managers change their market risk to a larger extent than the portfolio’s volatility and,
in general, the degree of persistence is larger for funds with a very low or a very high
exposure to a risk factor.
Similar are the findings for the style factors in the Carhart (1997) four-factor model. While
for the HML factor, the transition probabilities for staying in the same class are 49.7%.
34.4%, 32.4%, 44.4%, the transition probabilities for the SMB factor are 49.03%, 33.1%,
35.1%, 68.7%. For the momentum (UMD) factor, the transition probabilities are 42.9%,
32.7%, 31.3%, 46.9%. Therefore, over the whole sample, the persistence in the choice of
risk levels is particularly high for fund investing to a large extent in small caps (high SMB
factor). However, this finding is consistent with prior expectations because the choice of
risk level and its persistence is, at least partially, induced by a fund’s policy.
For the tracking error against the S&P 500, the diagonal transition probabilities are 61.9%,
36.8%, 32.5%, 62.4%. Therefore, the persistence of active and passive portfolio
management measured as the deviation from the index is substantial.
Overall, we find strong evidence for persistence in the choice of risk levels. In particular,
funds with a very high and very low exposure to specific risk factors show a high degree of
persistence. However, these results are not surprising because a number of factors and, in
particular, institutional restrictions induce a persistent behavior.
19
3.3. The Impact of Prior Performance
In this section, we turn to the impact of prior performance on the risk taking of mutual fund
managers. The complete empirical results are included in the appendix in Tables A1 and
A2. Due to the large amount of empirical data, we focus the interpretation on the results
shown in the Tables 4 and 5.
Table 4 shows the difference in transition probabilities for top- and poor-performing
mutual funds for risk-adjusted returns using the S&P 500 as benchmark index. For the
volatility, we find that fund managers with a poor performance, in general, strongly
decrease their portfolio volatility in the following calendar year. For example, the
difference in transition probabilities for funds with a volatility in the highest quartile is
18.9%. Only successful funds with a low volatility (in Q1) increase the volatility in the
following calendar year.
For the beta, the evidence is mixed. Funds with an exposure to the market risk above the
median (Q3 and Q4) take more market risk in the following calendar year, e.g. the
difference in transition probabilities for Q4 to Q4 is 9.8%. This indicates that successful
fund managers are 9.8% more likely to maintain their risk level than for unsuccessful
managers. In contrast, unsuccessful managers with a beta in Q1 increase their market risk
exposure significantly. For example, the difference in transition probabilities from Q1 to
Q2 is -8.4%. This indicates than poor-performing funds are 8.4% more likely to increase
their market risk exposure.
The style factors are interpreted as follows. A high loading (e.g. in Q4) on the value factor
(HML) indicates that a fund invests in value stocks. Vice versa, a low factor loading on the
value factor (Q1) is interpreted as an investment in growth stocks. A fund investing in
20
small caps shows a high exposure to the size factor (SMB) and a large-cap funds shows an
exposure to in the first quartile. Funds investing in momentum stocks have a high loading
on the UMD factor (Q4) and contrarian funds a low loading on UMD.
For the HML, SMB and UMD factor, there is overwhelming evidence for increased risk
taking by successful fund managers. Successful fund managers invest in the future heavily
in value stocks, small caps and momentum stocks.
For the loading on the value premium (HML), all differences in transition probabilities
ending in Q1 are negative and ending in Q4 are positive. For example, successful funds
having invested in growth stocks are 6.7% more likely to switch to a substantial value
investment (transition element Q1 to Q4) and poor-performing funds are 8.5% more likely
to continue the unsuccessful growth stock investments (transition element Q1 to Q1).
For the size exposure, the change in behavior is even stronger. All successful manager
regardless of their prior size exposure invest substantially in small caps. For example,
successful managers who have previously invested primarily in large caps are 6.8% more
likely to invest substantially in small caps than their unsuccessful counterparts (transition
probability Q1 to Q4).
For the momentum exposure, the previously observed pattern, i.e., increased risk-taking by
successful mangers, is also observable, but less evident. Material changes are observable
for fund managers having previously neglected momentum stocks (Q1). If these fund
managers achieved a good-performance they are 9.5% more likely to invest in the future
heavily in momentum stocks than poor-performing managers (transition probability Q1 to
Q4).
The tracking error as a measure of active portfolio management validates the findings for
other variables. Successful managers increase, in general, the tracking error and poor-
21
performing fund managers tend to decrease it. For example, successful fund managers are
17.0% more likely to maintain a tracking error in the highest quartile (Q4) compared to
unsuccessful fund managers.
Next, we analyze how portfolio managers respond to prior performance measured with the
Carhart four-factor model. As shown by Carhart (1997), the four-factor model explains a
high proportion of the cross sectional variance of the performance of mutual funds. After
accounting for a fund’s exposure against value and growth stocks, large and small caps,
and momentum stocks, he finds little evidence for persistence in the performance of mutual
funds.
Overall, a comparison of the results for returns risk-adjusted with the Carhart four-factor
model on the one side and with a one factor model, i.e. the S&P 500 as benchmark indicate
differences as shown in Table 5. While Table 4 indicates substantial and significant
changes in behaveor, in particular for the first and fourth quartiles, the results for the
Carhart four-factor model are less evident.
For the volatility, we find, in general, no significant evidence for a change in behavior.
However, there is little evidence for increased risk-taking by low performing funds. For the
Beta, the data confirm our previous findings. A good performance induces increased taking
of market risk in the following period. However, most findings are statistically
insignificant.
For the HML, SMB and UMD factor, the results differ somehow from previous findings
and are mixed. For HML, we find clear statistically significant pattern. For SMB findings
reverse. For UMD, results are ambiguous. For the Carhart four-factor, we find strong
evidence that successful fund managers abstain from small caps. For example, the
22
transition probability from Q4 to Q4 is -3.4%. This indicates that successful fund managers
tend to reduce their exposure to small caps compared to poor-performing fund managers.
After controlling for a fund’s style, we find that unsuccessful funds tend to change their
momentum strategy into different directions. For example, the transition probability Q2 to
Q2 is significantly positive, having a value of 8.1%. This indicates that successful funds
are 8.1% more likely to choose a comparable momentum level. Unsuccessful funds change
their strategy into both directions, a contrarian strategy and a stronger momentum strategy.
For the tracking error, superior performance induces a more passive investments style after
controlling for a fund’s style. However, this findings is only significant for the first quartile
transition probabilities.
3.4. Discussion
In this section, we discuss the results of our econometric analysis with respect to
theoretical models and with respect to other empirical findings.
Existing literature trying to explain the behavior of mutual fund managers (e.g., Brown et
al. (1996), Chevalier & Ellison (1997), Carpenter (2000), Busse (2001), and Carhart,
Kaniel, Musto & Reed (2002)) has focussed on incentives faced by mutual fund managers.
Incentives in the mutual fund industry are primarily driven by two factors, by the
compensation schemes and the behavior of investors. Standard compensation schemes in
the mutual fund industry are convex, i.e., fund managers take part in the positive
performance of their funds by receiving bonuses while they usually do not take part in the
negative performance of their funds. Portfolio managers have a call option on the portfolio
they are managing. Moreover, as a second important incentive factor, the intertemporal
behavior of investors increases the effect of convex compensation schemes. Investors
23
allocate a large proportion of new capital to funds with a high performance in the previous
period whereas they do not withdraw invested capital from poorly performing funds.
Therefore, if a manager’s salary depends on the assets under management, investors’
behavior induces a convex relation between fund performance and fund size. Overall, both
patterns lead in theory to excessive risk taking by mutual fund managers.
However, in our empirical analysis, we were unable to find evidence for such a behavior.
In general, these findings can be explained by a different setting in this study compared to
other empirical studies. In particular, we use a large sample of funds over a longer time
period and different measures of risk and return. Moreover, we impose less restrictive
assumptions for the empirical analysis, e.g., we do not assume any linear relation or a
normal distribution. In particular, Brown et al. (1996) solely focus on volatility as a
measure of risk and only use a rather small sample of funds, funds focussing on growth
stocks, over a time period of 15 years. Their analysis focusses on mid-year effects and they
find that funds performing poorly by mid-year increase their volatility for the rest of the
year. Busse (2001) uses a very similar methodology and the same data set as in Brown et
al. (1996), but with a daily frequency, and finds that the fund’s intra-year change is
attributable to changes in the volatility of common stocks and not related to changing
factor exposures or residual risk. Similar, Chevalier & Ellison (1997) analyze the impact of
past performance on fund flows using a semi-parametric approach. Their results confirm
prior expectations, i.e., the flow-performance relation creates incentives for fund managers
to adjust the riskiness of the fund depending on mid-year performance.
How can we explain increased risk taking after years of good performance and decreased
risk taking after years of poor performance? Our explanation is two-sided. First, poor-
performing managers follow a more passive strategy to minimize the risk of their own
24
future replacement. Relative performance and not absolute performance is relevant.
Second, successful managers take more risk, because they have become more confident in
their own skills. Success creates confidence. Basically, our analysis shows that a
combination of the models by Lynch & Musto (2003) for unsuccessful managers and Berk
& Green (2004) for successful managers describe the data best.
Lynch & Musto (2003) propose a model in which strategy changes only occur after periods
of bad performance. However, a priori, their model does not say how the strategy changes.
In their empirical analysis, they find evidence for a change of factor loadings. They find
that poor performers seem to increase their UMD loading and decrease their HML loading.
Neither market beta nor SMB loading is systematically affected by fund performance. The
different results by Lynch & Musto (2003) in comparison to our analysis might be due to
the shorter sample period in the analysis by Lynch & Musto (2003) and to the use of a non-
linear model in our analysis. Our analysis shows that, after a period of bad performance,
managers choose a passive investments style (lower tracking error), take less market risk,
decrease their exposure to value, and increase their exposure to large caps, and stocks with
a low momentum effect.
Berk & Green (2004) propose a model that incorporates two important features. First,
performance is not persistent, i.e., active portfolio managers do not outperform passive
benchmarks on average and, second, funds flows rationally respond to past performance.
In particular, they assume that investors behave as Bayesians, i.e., they update their beliefs
about a fund manager’s skill based on observed returns and prior beliefs. The same
argumentation can be applied to a manager’s belief about his own skills. Starting with
some prior confidence on his own skills, he learns about his skills and uses his skills in the
following time period. If skills require specific trading strategies, e.g., a fund manager has
25
special skills in selecting small caps or value stocks, an empirical analysis will show
patterns as we have observed.
Mutual fund managers behavior is more complex than assumed by theoretical models,
which usually capture only one aspect of the actual behavior. According to our analysis, a
combination of the models by Lynch & Musto (2003) and Berk & Green (2004) describes
the findings best.
4. Conclusion
How do mutual fund managers react to past performance? Theory suggests that good-
performing mutual fund managers reduce their risk level and poor-performing managers
take more risk because they do not bear the downside risk. However, such a behavior
might be unrealistic in actual life due to restrictions fund managers are facing, such as
tracking error restrictions. Moreover, other factors affecting the behavior of mutual fund
managers might be more important than pure compensation maximization. For example, if
relative performance is more important than absolute performance, they tend to take only
little idiosyncratic risk compared to their relevant benchmark.
In this paper, we analyze a large sample of US investments funds for a period of 20 years.
For each year, we compute different measures of style and risk. Overall, our analysis
extends the existing literature in a number of ways. In contrast to existing studies, we do
not solely focus on volatility as a measure of risk. We take also other measures such as the
beta and the tracking error, and style measures such as the high-minus-low (HML) factor,
the small-minus-big (SMB) factor, and the momentum (UMD) factor into account.
Furthermore, we use a robust, non-parametric approach and are therefore able to capture a
26
wide range of non-linear and asymmetric patterns because we do not impose any restrictive
distributional assumptions. Concerning the data basis, we do not use only a sub-group of
mutual funds, but a complete set of all US equity funds with a long time period of data.
Our analysis does not lend any support for the hypothesis that poor-performing fund
managers increase the risk level. We find that prior performance has a positive impact on
the choice of the risk level, i.e., successful fund managers take more risk in the following
time period. In particular, they increase the volatility, the beta and the tracking error and
assign a higher proportion of their portfolio to value stocks, small firms and momentum
stocks. Overall, poor performing fund managers switch to passive strategies. Unsuccessful
managers decrease the level of idiosyncratic risk and follow the relevant benchmark more
closely.
References
Berk, J. & Green, R. (2004), ‘Mutual fund flows and performance in rational markets’, Journal of Political Economy 112, 1269–1295. Borgelt, C. & Kruse, R. (2002), Graphical Models, John Wiley & Sons, New York. Brown, K., Harlow, W. & Starks, L. (1996), ‘Of tournaments and temptations: An analysis of managerial incentives in the mutual fund industry’, Journal of Finance 51, 85–110. Busse, J. (2001), ‘Another look at mutual fund tournaments’, Journal of Financial and Quantitative Analysis 36, 53–73. Carhart, M. (1997), ‘On persistence in mutual fund performance’, Journal of Finance 52, 57–82. Carhart, M. M., Kaniel, R., Musto, D. K. & Reed, A. V. (2002), ‘Learning for the tape: Evidence of gaming behavior in equity mutual funds’, Journal of Finance 68, 661–693. Carpenter, J. (2000), ‘Does option compensation increase managerial risk appetite?’, Journal of Finance 55, 2311–2331.
27
Chevalier, J. & Ellison, G. (1997), ‘Risk taking by mutual funds as a response to incentives’, Journal of Political Economy 105, 1167–1200. Cowell, R. G., Dawid, A. P., Lauritzen, S. L. & Spiegelhalter, D. J. (2003), Probabilistic Networks and Expert Systems, Springer, New York. Dangl, T., Wu, Y. & Zechner, J. (2004), ‘Mutual fund flows and optimal manager replacement’, Working Paper. University of Vienna. Daniel, K., Grinblatt, M., Titman, S. & Wermers, R. (1997), ‘Measuing mutual fund performance with characteristic-based benchmarks’, Journal of Finance 52, 1035–1058. Deli, D. N. (2002), ‘Mutual fund advisory contracts: An empirical investigation’, Journal of Finance 57, 109–133. Duda, R. O., Hart, P. E. & Stork, D. G. (2001), Pattern Classification, John Wiley & Sons, New York. Fama, E. & French, K. (1993), ‘Common risk factors in the returns on stocks and bonds’, Journal of Financial Economics 33, 3–57. Ghahramani, Z. (2001), ‘An introduction to Hidden Markov Models and Bayesian networks’, International Journal of Pattern Recognition and Artificial Intelligence 15, 9–42. Jensen, F. J. (2001), Bayesian Networks and Decision Graphs, Springer, New York. Jordan, M. I., Ghahramani, Z. & Saul, L. K. (1997), ‘An introduction to variational methods for graphical models’, Working Paper . Korb, K. B. & Nicholson, A. E. (2004), Bayesian Artifical Intelligence, Chapmann & Hall / CRC, New York. Kothari, S. & Warner, J. B. (2001), ‘Evaluating mutual fund performance’, Journal of Finance 56, 1985–2010. Lynch, A. & Musto, D. (2003), ‘How investors interpret past fund returns’, Journal of Finance 58, 2033–2058. Neapolitan, R. E. (2004), Learning Bayesian Networks, Prentice Hall, Upper Saddle River. Pearl, J. (1982), Reverend Bayes on inference engine: A distributed hierarchical approach, in ‘Proceedings, Cognitive Science Society’, Ablex, Greenwich, CT, pp. 329–334. Pearl, J. (2000), Causality: Models, Reasoning and Inference, Cambridge University Press, Cambridge.
28
Schmidt, B. (2003), ‘Hierarchical Bayesian models, holding propensity and the mutual fund flow-performance relation’, Working Paper. University of Chicago. Wermers, R. (2000), ‘Mututal fund performance: An empirical decomposition into stock-picking, style, transactions costs, and expenses’, Journal of Finance 55, 1655–1695.
29
Exhibits
Figure 1
Illustration of a Dynamic Bayesian Network The three main issues in the area of Bayesian Networks are (1) the question of representation, i.e., what is a Bayesian Network, (2) probabilistic inference, i.e., the updating of probability distributions for a query node given evidence for a particular node, and (3) the estimation of parameters for conditional probability distributions for a Bayesian Network based on sample data. Representation: A Bayesian Network consists of a set of variables, usually denoted as nodes (illustrated as circles). The arcs represent conditional dependencies in the network between nodes. Inference: Probabilistic inference denotes the updating of probability distributions for a query node given some evidence (posterior distribution). The Graph illustrates the probability updating for the query node TRT, i.e., the tracking error in Period T + 1, conditional on the evidence that RT, i.e., return in period T, was high. Learning: To learn the parameters for conditional probability distributions in a Bayesian Network maximum likelihood methods are applicable.
30
Figure 2 Dynamic Bayesian Network used in the empirical analysis
For a number of different measures of risk, we analyze the joint effect of the risk level in T and the risk-adjusted return in T on the choice of the risk level in T+1. The data set was provided by Reuters Lipper and consists of 1923 funds with return data from 1984 to 2004. As measures of risk we used: volatility (STD), the beta with respect to the market portfolio (MRP), the factor loading on the value premium (HML), the factor loading on the size premium (SMB), the factor loading on the momentum premium (UMD), and the tracking error (TE). A return is denoted by R. The tracking error and the beta have been computed with respect to the S&P 500 and the CRSP market portfolio using a one factor and a four-factor model, respectively (denoted as TESP500, TECarhart, MRPSP500, MRPCarhart. Similar, return R has been computed on a raw basis (without risk-adjustment), risk-adjusted in a one factor model with respect to the S&P 500 and to the Carhart (1997) four factor model (denoted as RRaw, RSP500, and RCarhart).
31
Table 1 Descriptive statistics for annual continuously compounded returns
The table shows the descriptive statistics for annual continuously compounded returns for all funds existing in one particular year. The data set is from Reuters Lipper.
Year Funds Mean Std. Skew Kurt Min 25% 50% 75% Max
1985 191 18.87 7.37 -0.01 3.67 -3.23 14.18 19.43 23.23 43.561986 216 0.49 10.80 -0.20 5.28 -48.43 -5.64 0.55 8.00 45.381987 243 -13.49 12.46 -0.23 5.87 -60.19 -19.86 -13.13 -5.38 42.811988 284 9.46 8.12 0.08 4.52 -15.31 4.27 9.58 14.36 46.101989 305 15.31 8.38 0.01 3.44 -9.40 10.36 14.95 20.95 41.451990 326 -11.70 8.79 -0.63 3.76 -41.48 -16.63 -10.80 -5.52 11.511991 350 26.28 12.08 -1.29 16.97 -75.62 18.99 25.39 32.88 63.081992 387 3.52 8.02 -0.72 7.93 -48.47 -0.39 3.59 7.29 30.101993 452 5.34 8.53 -1.14 10.06 -51.79 0.49 5.73 10.44 36.901994 539 -6.52 7.30 -0.54 5.32 -41.25 -10.34 -5.95 -2.41 21.081995 622 20.44 8.72 -0.36 5.07 -22.82 15.67 21.01 25.75 48.421996 701 9.39 9.09 -1.07 9.59 -61.24 4.93 9.56 14.72 44.061997 822 11.36 11.24 -1.18 7.27 -56.69 5.48 12.89 18.44 49.911998 977 6.57 15.34 -0.12 3.58 -48.04 -3.24 6.84 16.87 58.221999 1114 17.05 22.76 1.07 5.02 -53.06 1.48 13.49 27.79 136.392000 1233 -12.14 22.51 -1.52 9.89 -188.63 -23.45 -10.09 2.68 40.862001 1369 -11.83 16.82 -0.30 4.28 -90.89 -21.35 -12.61 -1.30 45.782002 1478 -26.35 11.34 -0.66 5.64 -103.74 -32.59 -26.08 -19.18 14.082003 1478 28.26 8.98 0.42 12.28 -58.39 22.29 26.70 33.06 97.56
32
Table 2 Transition probabilities between risk and return
The table shows the transition probabilities between different measures of risk and the subsequent return. * denotes a value statistically different from 0.25 on a 95% level and ** on a 99% level. Standard errors have been computed by bootstrapping. The table is interpreted as follows. Suppose a fund has in one particular year a volatility in the lowest quartile among all other funds. Then, the fund has a probability of 11.8% (first row, firstcolumn) to achieve a risk-adjusted return in the lowest quartile among all other funds. Analogously, the chance is 30.8% (first row, fourth column) to obtain a risk-adjusted return in the highest quartile among all other funds.
tofrom Q1 Q2 Q3 Q4STDT Q1 11.8%* 28.9%** 28.3%** 30.8%**
Q2 15.5%* 25.1% 30.6%** 28.6%**Q3 17.9%* 21.7%* 25.0% 34.4%**Q4 22.8%* 16.6%* 19.0%* 41.4%**
MRPSP500,T Q1 16.0%* 18.6%* 22.6%* 42.6%**Q2 15.1%* 22.4%* 27.8%* 34.5%**Q3 16.5%* 25.7% 27.4%** 30.2%**Q4 21.1%* 21.8%* 23.9% 33.0%**
HMLT Q1 24.0% 23.0%* 19.4%* 32.6%**Q2 15.7%* 28.0%** 30.0%** 26.2%Q3 13.1%* 24.7% 30.3%** 31.8%**Q4 17.8%* 15.6%* 22.2%* 44.2%**
SMBT Q1 21.7%* 28.2%** 25.7% 24.2%Q2 14.5%* 30.4%** 29.9%** 25.0%Q3 13.3%* 24.2% 29.6%** 32.7%**Q4 19.5%* 14.8%* 21.1%* 44.4%**
UMDT Q1 33.7%** 30.7%** 18.4%* 17.0%*Q2 20.3%* 32.1%** 26.5%** 21.0%*Q3 12.9%* 22.0%* 32.0%** 33.0%**Q4 12.9%* 14.3%* 23.2%* 49.4%**
TESP500,T Q1 14.3%* 29.2%** 30.8%** 25.5%Q2 18.1%* 25.1% 27.7%** 29.0%**Q3 18.0%* 19.0%* 22.5%* 40.3%**Q4 20.7%* 13.9%* 19.4%* 45.8%**
RSP500,T
33
Table 3 Transition probabilities between risk in T and T+1
The table shows the transition probabilities between different measures of risk in T and T+1. XXX denotes that the target (column) variable is the same variable as in the appropriate row. The table shows the results for the model with risk-adjustment using the S&P 500. * denotes a value statistically different from 0.25 on a 95% level and ** on a 99% level. Standard errors have been computed by bootstrapping. The table is interpreted as follows. Suppose a fund has in one particular year a volatility in the lowest quartile among all other funds. Then, the fund manger has selected with a probability of 50.4% (first row, first column) a return volatility in the lowest quartile among all funds in the next calendar year. Analogously, the chance is 2.6% (first row, fourth column) to select a volatility on the highest quartile among all other funds in the next calendar year.
to
from Q1 Q2 Q3 Q4STDT Q1 50.4%** 32.9%** 14.0%* 2.6%*
Q2 24.4% 37.8%** 29.7%** 7.9%*Q3 8.4%* 22.8% 41.2%** 27.4%Q4 1.2%* 6.3%* 22.2%* 70.1%**
MRPSP500,T Q1 46.0%** 28.7%** 17.6%* 7.5%*Q2 25.4% 31.0%** 27.9%** 15.5%*Q3 11.8%* 25.5% 36.4%** 26.1%Q4 4.7%* 13.8%* 27.0% 54.1%**
HMLT Q1 49.7%** 24.6% 15.5%* 9.9%*Q2 26.4% 34.3%** 25.0% 13.3%*Q3 14.9%* 27.7%** 32.4%** 24.8%Q4 11.5%* 15.4%* 28.5%** 44.4%**
SMBT Q1 49.3%** 29.5%** 14.7%* 6.4%*Q2 37.8%** 33.1%** 18.9%* 10.0%*Q3 15.4%* 17.7%* 35.1%** 31.7%**Q4 4.2%* 5.8%* 21.1%* 68.7%**
UMDT Q1 42.9%** 25.2% 18.0%* 13.7%*Q2 26.0% 32.7%** 24.5% 16.1%*Q3 16.1%* 27.8%** 31.3%** 24.6%Q4 11.4%* 15.2%* 26.3% 46.9%**
TESP500,T Q1 61.9%** 25.5% 9.1%* 3.4%*Q2 22.5% 36.8%** 25.4% 15.2%*Q3 7.4%* 23.9% 32.5%** 36.0%**Q4 1.7%* 9.8%* 26.0% 62.4%**
XXXT
M: RSP500,T
34
Table 4 Impact of prior performance on the choice of risk level (returns
adjusted with the S&P 500) The table shows the difference in transition probabilities between different measures of risk in T and T+1 for funds with a performance in the highest quarter in T and for funds with a performance in the lowest quarter in T. XXX denotes that the target (column) variable is the same variable as in the appropriate row. The table shows the results for returns adjusted with the S&P 500. * denotes a value statistically different from 0 on a 95% level and ** on a 99% level. Standard errors have been computed by bootstrapping. The results displayed in this table base on a risk-adjusted return using a one factor model and the S&P 500 as market portfolio. The results in the table have been computed as follows. Top-performing funds are funds with a return in the fourth quartile in one calendar year, poor-performing funds are funds with a return in the first quartile in one calendar year. Both groups have different transition matrices for the risk level in the next year. In this table, we show the difference of element-by-element subtraction of the transition matrices. The transition matrix of poor-performing funds has been subtracted from the matrix of top-performing funds. Therefore, positive elements indicate that the transition probability for top-performing funds was higher than for poor-performing funds and vice-versa.
to
from Q1 Q2 Q3 Q4STDT Q1 6.3% -1.5% -1.1% -3.6%**
Q2 -10.3%** -0.9% 7.4%* 3.8%*Q3 -8.5%** -9.0%** 0.0% 17.0%**Q4 -2.1%** -6.0%** -10.7%** 18.9%**
MRPSP500,T Q1 13.3%** -8.4%** -1.8% -3.0%**Q2 3.3% -6.8%** 3.3% 0.0%Q3 -5.8%** -4.7%** 1.7% 8.8%**Q4 -5.0%** -1.8% -3.0% 9.8%**
HMLT Q1 -8.5%** -3.6% 5.4%** 6.7%**Q2 -8.4%** -0.5% 2.3% 6.6%**Q3 -7.1%** -4.1% 5.8%* 5.4%*Q4 -9.8%** -0.5% 3.2%* 7.1%**
SMBT Q1 -6.7%* -3.1% 3.0% 6.8%**Q2 -11.4%** -1.8% 5.5%* 7.7%**Q3 -13.1%** -7.9%** 5.0%* 16.0%**Q4 -6.5%** -5.8%** -1.2% 13.6%**
UMDT Q1 -13.0%** -5.2%* 8.7%** 9.5%**Q2 -3.4% -1.4% 2.0% 2.7%Q3 -8.7%** 1.5% 9.5%** -2.2%Q4 -6.6%** -1.9% 5.3%** 3.2%
TESP500,T Q1 13.0%** -11.5%** -4.1% 2.7%*Q2 -5.8%* -4.3% 1.7% 8.4%**Q3 -6.6%** -5.0%* 0.9% 10.6%**Q4 -3.1%** -9.3%** -4.5%* 17.0%**
XXXT+1
Difference
35
Table 5 Impact of prior performance on the choice of risk level (returns
adjusted with the Carhart model) The table shows the difference in transition probabilities between different measures of risk in T and T+1 for funds with a performance in the highest quarter in T and for funds with a performance in the lowest quarter in T. XXX denotes that the target (column) variable is the same variable as in the appropriate row. The table shows the results for returns adjusted with the Carhart model. * denotes a value statistically different from 0 on a 95% level and ** on a 99% level. Standard errors have been computed by bootstrapping. The results in the table have been computed as follows. Top-performing funds are funds with a return in the fourth quartile in one calendar year, poor-performing funds are funds with a return in the first quartile in one calendar year. Both groups have different transition matrices for the risk level in the next year. In this table, we show the difference of element-by-element subtraction of the transition matrices. The transition matrix of poor-performing funds has been subtracted from the matrix of top-performing funds. Therefore, positive elements indicate that the transition probability for top-performing funds was higher than for poor-performing funds and vice-versa.
to
from Q1 Q2 Q3 Q4STDT Q1 7.0% 1.6% -5.8% -2.8%**
Q2 2.1% -3.8% 2.6% -1.0%Q3 1.0% 1.7% -0.1% -2.6%Q4 0.0% 0.0% -1.2% 1.4%
MRPSP500,T Q1 -0.2% -2.1% 4.0%* -1.6%Q2 -6.8%** -3.7% 7.6%** 2.8%Q3 -3.9%* -7.5%** 2.7% 8.6%*Q4 -2.3%** -1.2% 0.0% 2.9%
HMLT Q1 -3.4% -1.5% 2.4%* 2.5%*Q2 -5.9%** 7.1%** 2.1% -3.3%Q3 -4.6%* 2.4% 0.4% 1.7%Q4 0.0% -0.3% 0.0% -0.1%
SMBT Q1 15.5%** 1.4% -10.3%** -6.6%**Q2 7.4%** -0.3% -3.2% -3.7%*Q3 -3.9%* 0.0% -0.1% 4.1%Q4 -0.5% -0.2% 4.1%* -3.4%*
UMDT Q1 1.7% 1.2% 1.9% -4.9%**Q2 -2.0% 8.1%** -0.4% -5.5%**Q3 -7.2%** 0.6% 11.2%** -4.0%Q4 -2.6%* -0.5% 5.9%** -2.6%
TESP500,T Q1 30.4%** -6.9%** -18.9%** -4.4%**Q2 3.6% 3.6% -3.2% -4.0%Q3 -1.8%* 5.9%* -2.6% -1.4%Q4 -0.1% 0.0% 1.6% -1.5%
XXXT+1
Difference
36
Table A1
Impact of prior performance on the choice of risk level (returns adjusted with the S&P 500) The table shows the transition probabilities between different measures of risk in T and T+1 for funds with a performance in the highest quarter in T (first four columns), for funds with a performance in the lowest quarter in T (middle four columns), and the difference between these transition probabilities. XXX denotes that the target (column) variable is the same variable as in the appropriate row. The table shows the results for returns adjusted with the S&P 500. For the left and middle set of columns, * denotes a value statistically different from 0.25 on a 95% level and ** on a 99% level. For the difference between transition probabilities in the right set of columns, the null hypothesis is 0.00, i.e., we test whether this difference is statistically different from 0. Standard errors have been computed by bootstrapping.
to
from Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4STDT Q1 50.6%** 31.1%** 15.5%* 2.7%* 44.2%** 32.7%* 16.6%* 6.3%* 6.3% -1.5% -1.1% -3.6%
Q2 22.3% 35.4%** 29.8%* 12.3%* 32.7%* 36.3%** 22.4% 8.4%* -10.3%** -0.9% 7.4%* 3.8%Q3 4.8%* 16.1%* 39.5%** 39.4%** 13.4%* 25.2% 38.9%** 22.3% -8.5%** -9.0%** 0.0% 17.0Q4 0.3%* 2.6%* 14.3%* 82.5%** 2.5%* 8.6%* 25.1% 63.6%** -2.1%** -6.0%** -10.7%** 18.9
MRPSP500,T Q1 54.3%** 23.8% 14.8%* 6.9%* 40.9%** 32.2%** 16.7%* 10.0%* 13.3%** -8.4%** -1.8% -3.0%Q2 31.0%** 26.5% 26.0% 16.3%* 27.6% 33.3%** 22.6% 16.3%* 3.3% -6.8%** 3.3% 0.0Q3 13.8%* 23.3% 30.6%** 32.1%** 19.6%* 28.1% 28.8% 23.3% -5.8%** -4.7%** 1.7% 8.8%Q4 3.9%* 11.3%* 22.1%* 62.5%** 8.9%* 13.2%* 25.1% 52.6%** -5.0%** -1.8% -3.0% 9.8%
HMLT Q1 46.1%** 21.6%* 17.8%* 14.3%* 54.7%** 25.2% 12.4%* 7.5%* -8.5%** -3.6% 5.4%** 6.7%Q2 26.0% 28.8% 24.5% 20.4%* 34.5%** 29.4%** 22.1%* 13.8%* -8.4%** -0.5% 2.3% 6.6%Q3 14.3%* 18.7%* 31.9%** 34.9%** 21.4% 22.8% 26.1% 29.5%** -7.1%** -4.1% 5.8%* 5.4%Q4 7.7%* 13.3%* 26.2% 52.5%** 17.6%* 13.9%* 2.0% 45.4%** -9.8%** -0.5% 3.2%* 7.1%
SMBT Q1 38.7%** 24.7% 22.2%* 14.2%* 45.5%** 27.9% 19.2%* 7.3%* -6.7%* -3.1% 3.0% 6.8%Q2 24.0% 29.2%** 25.3% 21.3%* 35.5%** 31.1%** 19.7%* 13.6%* -11.4%** -1.8% 5.5%* 7.7%Q3 7.2%* 10.7%* 36.0%** 45.9%** 20.3%* 18.7%* 30.9%** 29.9%** -13.1%** -7.9%** 5.0%* 16.0Q4 0.8%* 2.3%* 19.1%* 77.6%** 7.4%* 8.1%* 20.4%* 63.9%** -6.5%** -5.8%** -1.2% 13.6
UMDT Q1 33.2%** 17.6%* 24.9% 24.1% 46.3%** 22.8%* 16.2%* 14.6%* -13.0%** -5.2%* 8.7%** 9.5%Q2 25.3% 24.6% 25.3% 24.5% 28.8%* 26.1% 23.1% 21.8%* -3.4% -1.4% 2.0% 2.7Q3 13.3%* 23.8% 32.2%** 30.6%** 22.1% 22.2% 22.6% 32.8%** -8.7%** 1.5% 9.5%** -2.2Q4 8.3%* 11.4%* 25.1% 55.0%** 14.9%* 13.3%* 19.8%* 51.8%** -6.6%** -1.9% 5.3%** 3.2
TESP500,T Q1 55.0%** 27.1% 11.4%* 6.3%* 42.0%** 38.7%** 15.5%* 3.6%* 13.0%** -11.5%** -4.1% 2.7%Q2 13.1%* 35.0%** 27.3% 24.3% 19.0%* 39.4%** 25.0% 15.8%* -5.8%* -4.3% 1.7% 8.4%Q3 2.1%* 19.7%* 33.4%** 44.5%** 8.8%* 24.8% 32.5%** 33.8%** -6.6%** -5.0%* 0.9% 10.6Q4 0.3%* 4.7%* 20.8%* 74.0%** 3.5%* 14.0%* 25.4% 56.9%** -3.1%** -9.3%** -4.5%* 17.0
XXXT+1
DifferenceXXXT+1
RSP500,T=4Q RSP500,T=1QXXXT+1
Table A2 Impact of prior performance on the choice of risk level (returns adjusted with the Carhart model)
The table shows the transition probabilities between different measures of risk in T and T+1 for funds with a performance in the highest quarter in T (first four columns), for funds with a performance in the lowest quarter in T (middle four columns), and the difference between these transition probabilities. XXX denotes that the target (column) variable is the same variable as in the appropriate row. The table shows the results for returns adjusted with the Carhart model. For the left and middle set of columns, * denotes a value statistically different from 0.25 on a 95% level and ** on a 99% level. For the difference between transition probabilities in the right set of columns, the null hypothesis is 0.00, i.e., we test whether this difference is statistically different from 0. Standard errors have been computed by bootstrapping.
to
from Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4 Q1 Q2 Q3 Q4STDT Q1 47.3%** 32.2%* 17.5%* 2.9%* 40.2%** 30.5%* 23.4% 5.8%* 7.0% 1.6% -5.8% -2.8%*
Q2 23.6% 32.5%** 33.4%** 10.4%* 21.4% 36.3%** 30.7%* 11.4%* 2.1% -3.8% 2.6% -1.0%Q3 8.1%* 22.2% 38.4%** 31.1%** 7.0%* 20.5%* 38.5%** 33.8%** 1.0% 1.7% -0.1% -2.6%Q4 1.3%* 6.4%* 20.7%* 71.5%** 1.5%* 6.4%* 21.9%* 70.0%** 0.0% 0.0% -1.2% 1.4%
MRPSP500,T Q1 42.3%** 26.8% 21.1%* 9.5%* 42.6%** 29.0%* 17.0%* 11.2%* -0.2% -2.1% 4.0%* -1.6%Q2 19.0%* 28.2% 31.3%** 21.3% 25.8% 31.9%** 23.6% 18.5%* -6.8%** -3.7% 7.6%** 2.8%Q3 12.0%* 20.5%* 32.9%** 34.5%** 15.9%* 28.0% 30.1%** 25.8% -3.9%* -7.5%** 2.7% 8.6%*Q4 4.8%* 12.3%* 23.4% 59.3%** 7.1%* 13.5%* 22.8% 56.4%** -2.3%** -1.2% 0.0% 2.9%
HMLT Q1 50.9%** 24.1% 14.4%* 10.4%* 54.3%** 25.6% 12.0%* 7.9%* -3.4% -1.5% 2.4%* 2.5%*Q2 29.1%* 32.9%** 24.6% 13.2%* 35.0%** 25.8% 22.4%* 16.5%* -5.9%** 7.1%** 2.1% -3.3%Q3 16.4%* 25.1% 31.4%** 26.9% 21.0% 22.7% 30.9%** 25.1% -4.6%* 2.4% 0.4% 1.7%Q4 16.2%* 14.8%* 26.0% 42.8%** 16.1%* 15.1%* 25.5% 43.0%** 0.0% -0.3% 0.0% -0.1%
SMBT Q1 55.9%** 26.4% 11.1%* 6.4%* 40.3%** 24.9% 21.5%* 13.1%* 15.5%** 1.4% -10.3%** -6.6%*Q2 37.3%** 29.9%** 19.3%* 13.3%* 29.9%** 30.3%** 22.5% 17.1%* 7.4%** -0.3% -3.2% -3.7%Q3 10.6%* 14.8%* 34.2%** 40.2%** 14.6%* 14.8%* 34.4%** 36.0%** -3.9%* 0.0% -0.1% 4.1%Q4 4.1%* 6.0%* 23.4% 66.3%** 4.6%* 6.2%* 19.2%* 69.8%** -0.5% -0.2% 4.1%* -3.4%
UMDT Q1 46.4%** 22.4% 17.8%* 13.2%* 44.6%** 21.2%* 15.9%* 18.1%* 1.7% 1.2% 1.9% -4.9%*Q2 26.5% 35.0%** 22.4% 15.9%* 28.7% 26.9% 22.8% 21.5%* -2.0% 8.1%** -0.4% -5.5%*Q3 16.1%* 25.3% 32.9%** 25.5% 23.3% 24.7% 21.6% 30.2%* -7.2%** 0.6% 11.2%** -4.0%Q4 12.7%* 14.3%* 27.8%* 45.0%** 15.3%* 14.9%* 21.9%* 47.7%** -2.6%* -0.5% 5.9%** -2.6%
TESP500,T Q1 67.1%** 24.0% 5.3%* 3.4%* 36.7%** 31.0%* 24.3% 7.9%* 30.4%** -6.9%** -18.9%** -4.4%*Q2 18.7%* 37.8%** 25.5% 17.8%* 15.0%* 34.2%** 28.8% 21.9% 3.6% 3.6% -3.2% -4.0%Q3 4.2%* 24.9% 31.9%** 38.7%** 6.1%* 19.0%* 34.6%** 40.2%** -1.8%* 5.9%* -2.6% -1.4%Q4 1.6%* 10.0%* 26.7% 61.5%** 1.8%* 9.9%* 25.1% 63.0%** -0.1% 0.0% 1.6% -1.5%
XXXT+1
DifferenceXXXT+1
RCarhart,T=4QXXXT+1
RCarhart,T=1Q